Why do owls have three eyelids?

Owls are one of the most popular species of birds because of their phenomenal vision.  Their eyes are considered to have a very long and wide range making some people describe them as having binocular vision.  With so much focus on the owl’s eyes, many people have also discovered that these birds have actually three sets of eyelids.  Each of these three eyelids actually serves a different purpose which is why they exist in the first place.  The first eyelid is intended for blinking.  As with many other animals, the owl’s eyes also need some blinking for lubrication and cleaning purposes.  Without the ability to blink, the owl’s eyes would easily become dry or injured by constant contact with dirt or dust.  The second eyelid, meanwhile, is designed for sleeping.  Whenever an owl decides to take a nap or a prolonged rest, for example, this second eyelid is the one used for this specific purpose.  The last eyelid in the owl’s eyes basically serves the purpose of keeping the eyes in a good and healthy condition.

With the different functions of their three eyelids, the owls also make use of their eyes to their advantage.  They are mostly active at nighttime, so they need their large eyes to have a very long and wide range to possibly find food and avoid their predators.  The owl’s huge eyes are also able to process light and dark images efficiently as they are often exposed to low levels of light during the night.  With their reputation for having the best night vision, some people thought that owls may have problems seeing during the daytime.  The fact is that the owl’s eyes are also very powerful and efficient even during the daytime.  With their three eyelids, the owls can basically maximize the use of their eyes which somewhat represents their most valuable asset.